The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

Underwater Camouflage

Many underwater creatures are adept at camouflage and mimicry. Both predators and prey sometimes use camouflage so cleverly that even humans may be fooled. A few years ago I was snorkeling off the west coast of the Big Island of Hawaii when an odd movement on the sea floor attracted my attention. At first it looked like a leaf moving with the currents but I wondered why it wasn't floating. I soon realized that my leaf was actually a leaf scorpionfish (Taenianotus triacanthus). This creature is suited perfectly to his name. Not only does it look leaf-like but it also swims in such a way to resemble a leaf tumbled by the currents. As an ambush predator, it's perhaps not as important to look like a leaf, which many sea-going animals have likely never seen, as it is to not look like a potential predator.

My next encounter was with a devil scorpionfish (Inimicus didactylus) -- at the center of the bottom photo. Masters of camouflage, the devil scorpionfish pretends to be a stone or a piece of coral, depending on the particular background where it happens to settle. It can also change its colors to blend in with its surroundings. Though usually motionless, it's amazingly fast when it strikes at prey or stings a would-be predator. Its sting is quite venomous; it won't kill you, but stepping on or touching one could land you in the hospital.